Clamps for joining and sealing tubular conduits such as truck exhaust pipes in end-to-end relation using stretchable metal bands are known. For example, one such clamp is disclosed in U.S. Pat. No. Re. 30,042.
Band clamps are sometimes utilized in lap joints. A lap joint is formed when an end of one conduit or pipe having a first diameter is placed inside the end of a second conduit or pipe having a diameter larger than the first diameter. Because the second conduit overlaps the first conduit, it is said to form a lap joint. At the seam where the joint is formed, there is a step, due to the differences in diameter of the two conduits. Band clamps have been used to wrap around the joint to secure it in place and to help effect a tight seal between the two conduits.
Band clamps have sometimes utilized a spacer bar to help effect a strong lap joint. One example of this is shown in U.S. Pat. No. 4,312,526.